From the attack on privacy and Cryptolocker to Eric Snowden and the NSA, it's been a challenging year.

Perhaps more than in recent history, Internet security issues went global this year especially with the revelations that the United States electronically spied on just about everyone. But there have been other significant ups and downs as well. Here we take a look at some of the important Internet security stories of the year.

US Secretary of State John Kerry (R), and Estonian Foreign Minister Urmas Paet (L), sign the US Estonia Partnership Statement at NATO headquarters in Brussels Dec. 3, 2013. The statement affirms the commitment of both countries to continue working together to enhance an open, interoperable, secure and reliable information and communications infrastructure and to prioritize openness and innovation on the Internet.

The forensics lab's evidence room is pictured inside the Microsoft Cybercrime Center, the new headquarters of the Microsoft Digital Crimes Unit, in Redmond, Wash. Microsoft, has launched a revamped attack against criminal hackers by bringing together security engineers, digital forensics experts and lawyers trained in fighting software pirates under one roof at its new Cybercrime Center.

The man who launched the furor: Edward Snowden, a former contractor at the National Security Agency (NSA), is seen during news broadcast on a screen at a shopping mall in Hong Kong June 16, 2013. Through his public disclosures via the Guardian newspaper the world found out that not only does the NSA collect phone records from the U.S. telecom firms, it can get user data from Microsoft, Google, Yahoo, Facebook, PalTalk, YouTube, Skype, AOL and Apple, including e-mail, chat, video, photos, stored data, VoIP, file transfer and other material under what’s called its PRISM program.

An illustration shows the logos of Google and Yahoo connected with LAN cables in a Berlin office. Stories this year indicated the US National Security Agency has tapped directly into communications links used by Google and Yahoo to move huge amounts of email and other user information among overseas data centers. Snowden disclosures appeared to show the agency has used weak restrictions on its overseas activities to exploit major U.S. companies' data to a far greater extent than realized.

A woman stands in front of a shelf with Internet security software at an electronic retailer in Berlin. In July Germans were reportedly snapping up security software following revelations that American surveillance programs have tapped citizens' private messages.

A protester holds a placard showing U.S. President Barack Obama with the phrase "Yes we scan" during a demonstration against the National Security Agency (NSA) and in support of U.S. whistleblower Edward Snowden.

Satellite dishes are seen at Britain's spy agency GCHQ's outpost at Bude, close to where trans-Atlantic fiber-optic cables come ashore in Cornwall, southwest England. GCHQ has tapped fiber-optic cables that carry international phone and internet traffic and is sharing vast quantities of personal information with the U.S.

President Barack Obama speaks about the National Security Agency's secret collection of telephone records from millions of Americans during a visit to San Jose. The debate over whether the government is violating citizens' privacy rights while trying to protect them from terrorism escalated dramatically in June amid reports that authorities have collected data on millions of phone users and tapped into servers at nine Internet companies.

An Internet user surfs the 'Net at a branch of the state-run telecommunications company, ETECSA, in Havana. Cuba began offering broader Internet access through 118 outlets around the country, according to a decree in the government's Official Gazette, in a step long awaited by many Cubans. The decree made clear that the new Internet access would be closely monitored, warning users it could not be used to "endanger or prejudice public security, or the integrity and sovereignty of the nation."

U.S. Secretary of State John Kerry attends a news conference in Beijing during the spring. China and the United States said they will set up a working group on cyber-security, as the two sides moved to ease months of tensions and mutual accusations of hacking and Internet theft.

A reporter of the YTN news channel prepares to report live in front of the Cyber Terror Response Center of the Korean National Police Agency in Seoul. A hacking attack in March hit the network servers of television broadcasters YTN, MBC and KBS as well as two major commercial banks, Shinhan Bank and NongHyup Bank. About 32,000 computers at the organizations were affected, according to the South's state-run Korea Internet Security Agency, adding it would take up to five days to fully restore their functions.

Lawyer Yasser Latif Hamdani (C) speaks with colleagues at his office in Lahore. Hamdani, who is suing the Pakistani government on behalf of internet freedom activists, said while some of the hundreds of web pages he had found blocked were pornographic, most were secular or sites belonging to religious minorities. The government is now testing Canadian software that can block millions of sites a second. The censorship helps shape the views of 180 million Pakistanis on militancy, democracy and religion. Activists say liberal voices are increasingly silenced while militants speak freely, according to Reuters.

The European nonprofit spam filtering company Spamhaus reportedly fended off DDoS, or distributed denial-of-service attacks, that briefly took the site offline in March and caused widespread congestion on the Web. Spamhaus creates blacklists of servers that spammers use to send messages for e-mail providers, so providers can then filter spam for their users.

Twitter said in a February blog post that hackers gained access to passwords and other information on as many as 250,000 user accounts. Twitter said the passwords were encrypted and it reset them as a “precautionary measure.”

Google agreed to pay a $7 million fine to settle a multi-state investigation into Google’s interception of personal e-mails, passwords and other sensitive information transmitted several years ago over unprotected wireless networks in neighborhoods. Google didn’t acknowledge any wrongdoing in the settlement that covers 38 states and the District of Columbia. In this photo, Google Director of Public Policy Alan Davidson gives testimony during a Senate Judiciary Committee hearing titled "Protecting Mobile Privacy: Your Smartphones, Tablets, Cell Phones and Your Privacy" on Capitol Hill.

The latest iteration of a long-time online ransomware scourge, Cryptolocker events surged with a vengeance in November. US –CERT wrote in a warning: CryptoLocker is a new variant of ransomware that restricts access to infected computers and demands the victim provide a payment to the attackers in order to decrypt and recover their files. As of this time, the primary means of infection appears to be phishing emails containing malicious attachments.

Federal prosecutors in New York charged eight suspects in what was described as a cyber theft ring with stealing $45 million from 27 banks around the world by hacking into them and committing crimes such as drastically increasing amounts available through credit cards. Their crimes are said to include withdrawing $400,000 in 750 separate ATM transactions at more than 140 locations in New York City in less than three hours and later withdrawing $2.4 million in 3,000 ATM withdrawals in just over 10 hours. Here we see images taken from the phone of a suspect, who was one of the individuals charged.